Telephone



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B. PICKERING. TELEPHONE.

No. 498,919. PatentedJune 6, 1893.

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B. PIGKE RING. TELEPHONE.

No. 498,919. Patented June 6, 1893.

UNITED STATES PATENT OFFICE.

BARTON PIOKERING, OF DAYTON, OHIO.

TELEPHONE.

SPECIFICATION forming part of Letters Patent N 0. 498,919, dated June 6, 1893. Application filed October 4, 1880. Serial No. 18,302. (ModeL) To all whom it may concern.-

Be it known that I, BARTON PICKERING, of Dayton, in thecounty of Montgomery and State of Ohio, have invented a new and useful Magneto-Electric Telephone, of which the following is a specification.

My improvements relate to the class of telephones using a permanent magnet.

My invention consists in the combination and construction of parts, as hereinafter described and claimed, whereby the magnetic force may be regulated and adapted to the elect-ro-magnetic force, without adjustment of the electro-magnetic core in its relation to the diaphragm.

Figure 1 is a cross-section on the line 0000 of Fig. 2. Fig. 2 is a side elevation of the instrument. Fig. 3 is a longitudinal section of the same.

The case consists of two parts, A, the mouth or car piece, and B the part to which the permanent magnet is attached, the induction coil and binding screws. The diaphragm is held between the parts of the case, and when placed together, they are secured by screws entering from the side.

The permanent magnet O is made of a flat bar of steel of uniform thickness, bent flatwise near its center, with poles arranged parallel; near the ends, and directly opposite, are orifices provided with threads to receive the electro-magnet, and the adjusting or regulating screw. There is a curved extension with orifice G, beyond the dotted line 8, s, which is not essential to the instrument, but as a part is convenient as a means of suspending the instrument on a hook or button. The part of magnet projecting from the case is admirably adapted for a handle for the instrument. A plane bar magnet,such as if the magnet were separated at the dotted line cit-would answer an excellent purpose, combined with the case and other parts as herein set forth. The magnet is attached to the case by one pole being placed in a mortise of the part B; and is there secured by wood screws entering the back part.

The electro-magnet O, is made hollow from the end next the diaphragm, to near the outer end. On this end is a thread to enter the orifice of the magnet, and is also slotted for a screw F, opposite the electro-magnet, which i may be either solid or hollow. When screwed against the electro-magnet it acts as an armature, to preserve unimpaired the power of the magnet, and thereby diminishes the inductive force of the magnet; and the withdrawal leaves with the magnet its amplitude of force, diminishing as the withdrawal pr0ceeds,- until its neutralizing power is quite destroyed.

The rear part of the case is recessed, and into this recess the binding screws enter from the back. Through this part holes are pierced, through which terminals of the inductive coil enter the recess to be connected to the binding screws D. To these are attached the conducting wires, which convey sounds by electrical undulations induced by sound-waves resulting in diaphragmatic vibrations.

The instrument may be used both as a transmitter and receiver, but is best adapted to use as a receiver in microphone transmission,and the adjustment is with a view to such use.

Telephones are adjustable with screws changing the relative position of the pole to the diaphragm, but in this manner of adjustment, the screw soon becomes loose, and this renders the instrument irregular in its action. In the operation of telephones, the best results are produced bya very close adjustment of the magnet or electro-magnet to the diaphragm; and when thus adjusted, with a powerful voltaic current the diaphragm is caught or drawn against the pole, thus impairing the action, which is obviated by using the adjusting or regulating screw, in combination with other parts as herein set forth.

The hollow electro-magnetic core 0, possesses an advantage over the solid core by pro-3 ducing a smoother and less metallic sound of the diaphragm.

I am aware that the relation of the permanent magnet, electro-magnet, helix and diaphragm have been used substantially as in this instrument; but the form of the magnet C and its relation to the case, the construction of the case, the adjusting or regulating screw F, and the hollow electro-magnet O, are features I regard as my invention. The free end of the permanent magnet is brought magnetically in proximity to the attached pole, and said free end vibrates responsively to the inductive electric wave, and thus adding intensity to the electro-motor force and thereby amplifying the sound.

Having described my invention, WhatI desire to secure by Letters Patent is- 1. In an electric telephone provided with a permanent magnet having parallel poles an adjusting or regulating screw inserted in and near one terminal of a permanent magnet of a single piece of metal and antagonizing an electro-magnet in the opposite pole, to modify the magnetic force exerted on the inductive coil and diaphragm, substantially as set forth.

2. In an electric telephone an adjustable screw inserted in and near one end of a permanent magnet with parallel poles capable of being brought in contact with the inter-polar end of the electro-magnet held in the opposite pole for the purpose of preserving said magnet from impairment, substantially as set forth.

3. In an electric telephone, the permanent magnet C, with screw threads through both poles, respectively for the adjusting screw and electro-magnet O, in combination with case A, B, diaphragm E, and helix n, substantially as set forth.

4. In a magnetic telephone the hollow electro-magnet with outer end closed to serve as a resonator, and to give increased magnetic susceptibility, in combination with the permanent magnet, inductive coil, and diaphragm, substantially as set forth.

5. In combination with the magnet having parallel poles and suitably formed for the application of the ear or mouth in telephonic communication, substantially as shown and described.

BARTON PIOKERING.

Witnesses:

J NO. W. SWAVELY, W. 0. Nelson. 

